The subject of the invention is an elastic coupling device for connecting two pieces in rotation.
Such a device is, in particular, for connecting the output of a tubular motor to the winding tube of a roller shutter or the like, for example as provided in document EP-A-0 135 731 for winding an awning. The elastic coupling allows the motor to turn for a few moments longer when the awning reaches the top stop before the stop device reacts. This makes it possible to absorb variations in length of the fabric of the awning and to guarantee a stop position against the stops.
In the roller blind described in document EP-A-0 684 362, an elastic coupling makes it possible to maintain a pressure on a lock, this pressure being necessary for its proper operation.
In the stop device for the roller shutter described in document DE 44 40 449, a clearance wheel is provided, which allows detection of the moment when the shutter encounters an obstacle by means of observation of the rotation of the winding shaft relative to the shaft for entraining the winding shaft. An elastic coupling could be used instead of the clearance wheel.